I have tried all ways to boot the PCLOS iso from grub2 and it either
dies with kernel panic (can't find init) or cannot find the loop file
which I assume is livecd.sqfs.
In the legacy case I can see it being found on sda1 (it searches all
available drives and stops at sda1 having found it) as that is where I
extracted it.
In grub2 I cannot figure a way to tell it to search the loop mounted iso
for the livecd.sqfs (I remove it from mainboot for grub2 tests)
The initrd runs fine and hardware detection is OK - until it tries to
hand over to the live image.